PeepCode ActiveMerchant

ActiveMerchant is a new e-book written by Cody Fauser and produced by Geoffrey Grosenbach's PeepCode which, unsurprisingly, is about the Active Merchant Ruby library and Rails plugin (past Ruby Inside reference). Cody Fauser is a key developer on the Active Merchant project, so all the knowledge is from the "horse's mouth," as it were! The Active Merchant library was initially developed as part of the Shopify e-commerce system, and is an excellent library for interacting with payment gateways from Ruby (and Rails) code. It's been in production use handling tens of thousands of payments since 2006 and it now has support for several payment gateways, including PayPal, Authorize.Net, and TrustCommerce.